1. Field of the Invention
The present invention relates to non-zero dispersion shifted optical fibers (NZDSF), or NZDS fibers, or NZ-DSF's.
2. Technical Background
Telecommunication systems, in both submarine and terrestrial deployments, require optical fiber which is capable of transmitting signals for long distances with as little signal degradation as possible. As new technologies are further developed, such as wavelength division multiplexing (WDM) and higher channel speeds, an ever-growing demand for network bandwidth is heightened. However, optical fiber attributes such as attenuation and bend loss are major contributing factors to the degradation of signals. Reduction of one or more of these factors would help to reduce or even eliminate the number of signal amplifications required in a network, which could reduce the cost of the network and increase the network efficiency.
Wavelength division multiplexing (WDM) systems have operated around the 1550 nm wavelength region, defined herein as including the C-band, and the L-band, which includes wavelengths between about 1565 nm to about 1625 nm. Some known fibers have a zero dispersion wavelength located outside the operation window which may help prevent nonlinear penalties such as four-wave mixing (FWM) and cross-phase modulation (XPM). However, the attenuation of known NZDSF fibers is not among the lowest of fibers.
Preferably, coarse wavelength division multiplexing (CWDM) systems and applications operate in the WDM 1550 nm window, i.e. in the C-and L-bands, in the S-band (between about 1450 nm and about 1525 nm), and in the 1310 nm window (between about 1280 nm and about 1330 nm).